Fabrıcatıon Of Mıs Hemt Passıvated By Ald For Hıgh Voltage And Low Leakage Current

Thesis Type: Postgraduate

Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey

Approval Date: 2019




In this study, AlGaN/GaN heterostructures on silicon have been used to fabricate and characterize metal-insulator-semiconductor (MIS) high electron mobility transistors (HEMT). Atomic layer deposited (ALD) aluminum oxide (Al2O3) gate dielectric has been used to decrease leakage current. Different Al2O3 layer thicknesses have been used to minimize current leakages to obtain a high voltage MIS HEMT. The trend in gate leakage, threshold voltage and breakdown voltage was studied for the fabricated devices. A negative shift in the threshold voltage was observed for increasing Al2O3 thickness. Gate leakage and breakdown voltage have improved with the use of Al2O3 gate dielectric. An increase in breakdown voltage and a decrease in gate leakage was observed as the passivation thickness decreased.